Liquid fuel pumping apparatus



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, LIQUID FUEL PUMPING APPARATUS 2 Sheets-Sheet 1 Filed June 26, 1968 w mg %//%U%%vv// WW x I E NTOR :A en w v4 Nam Kemp,

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ATTORNEYS M y 1970 K. A. w. KEMP ETAL 3,509,823

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ATTORNEYS United States Patent 3,509,823 LIQUID FUEL PUMPING APPARATUS Kenneth Albert Walters Kemp, Ealing, and Paul Edgar Glikin, Hendon Way, England, assignors to 'C.A.V. Limited, London, England Filed June 26, 1968, Ser. No. 740,247 Claims priority, application Great Britain, July 4, 1967, 30,753/ 67 Int. Cl. F04b 13/ 02; F04d 15/00; F02m 39/00 US. Cl. 417206 6 Claims ABSTRACT OF THE DISCLOSURE A liquid fuel pumping apparatus for supplying fuel to an internal combustion engine and comprising an injec-' tion pump to which fuel is supplied by way of an inlet passage, the inlet passage registering in turn with the ends of a pair of cylinders, containing movable shuttles, respectively one of said cylinders delivering fuel to the injection pump whilst the other cylinder is receiving fuel from a feed pump under the control of a throttle for subsequent delivery to the injection pump.

This invention relates to liquid fuel pumping apparatus for supplying fuel to an internal combustion engine having an even number of cylinders, the apparatus being of the kind comprising an injection pump which is adapted to be driven in timed relationship with the engine, and which during an injection stroke delivers a predetermined quantity of fuel, a rotary distributor member having a delivery passage through which during an injection stroke, fuel flows from the injection pump to one of a plurality of outlet ports, the distributor member also having an inlet passage through which fuel flows to the injection pump during a filling stroke thereof, the apparatus also including a feed pump for supplying fuel to the injection pump and a throttle for control-ling the quantity of fuel supplied by the feed pump.

The object of the invention is to provide such an apparatus in a simple and convenient form.

According to the invention in an apparatus of the kind specified the inlet passage is arranged to register during successive filling strokes alternately, with a pair of inlet ports, the inlet ports being in communication respectively With one end of a pair of cylinders, each cylinder containing a slidable shuttle, and the distributor member is provided with a feed groove or the equivalent through which fuel from the feed pump under the control of the throttle, flows to said ends of the cylinders for subsequent delivery to the injection pump.

In the accompanying drawings:

FIG. 1 is a sectional side elevation of one example of a liquid fuel pumping apparatus in accordance with the invention and FIG. 2 is a section on the line 22 of FIG. 1.

In one example of a liquid fuel pumping apparatus in accordance with the invention, and as shown in the drawings, there is provided a body part 10 in which is mounted a rotary cylindrical distributor member 11. The distributor member 11 is adapted to be driven in timed relationship with an engine with which the apparatus is associated and is coupled to a drive shaft 12. At one end of the distributor member there is mounted the rotary part of a fuel feed pump 13 which has an inlet 14 for liquid fuel, and an outlet 15. Moreover, the inlet and outlet are interconnected through a valve 16 which controls the output pressure of the fuel delivered by the feed pump in a manner so that it is dependent upon the speed at which the apparatus is driven. The feed pump 13 is of the vane type and the valve incorporates a spring loaded ball which controls the effective size of a spill orifice. The inlet 14 of the feed pump is in communication with a fuel inlet 17 formed in the body part and which in use, is connected to a source of liquid fuel.

Also provided is an injection pump and this comprises an annular cam ring 18 mounted within the body part and having a plurality of pairs of diametrically disposed and nwardly projecting cam lobes (not shown). Also forming part of the injection pump is a pair of pumping plungers 19 which are located within a transversely extending bore 20 formed in the distributor member. As the distributor member rotates, inward movement is imparted to the pumping plungers 20 by the interaction of rollers 21 mounted at their outer ends respectively with the lobes of the cam ring 18.

The transversely extending bore is in communication with a longitudinal bore 22 formed in the distributor member and which at one point is provided with a radially disposed delivery passage 23. The delivery passage is arranged to register in turn and as the distributor member rotates, with a plurality of outlet ports 24 which are formed in the body part. In the particular example, eight such outlet ports are provided and these are equi-angularly spaced about the periphery of the distributor member. Theoutlet ports are adapted for connection respectively to the injection nozzles 25 of the associated engine, and the communication between the delivery passage and an outlet port occurs during the time when the pumping plungers 19 are moved inwardly by the cam lobes.

At another point in the distributor member four equiangularly spaced and radially extending inlet passages 26 are formed, and the inner ends of these passages are in communication with the longitudinal passage 22. Moreover, alternately positioned relative to the inlet passages and formed on the periphery of the distributing member, are four feed grooves 27, each of which is in communication with a first circumferential groove formed in the periphery of the distributing member. This groove is in communication with the outlet 15 of the feed pump by way of a throttle 28 which controls the flow of fuel from the feed pump through a passage 29. The setting of the throttle is under the control of a speed sensitive governor (not shown) the characteristic of which can be adjusted by the operator. Furthermore, formed in the body part are a pair of inlet ports 30, 31 (FIG. 2) which are positioned to register with the inlet passages 26 and the feed grooves 27. The inlet ports 30, 31 are spaced circumferentially by a distance which is equal to the spacing between a feed groove and the adjacent inlet passages.

The inlet ports communicate respectively with the inner ends of a pair of cylinders 32, 33 formed in the body part, each cylinder containing a freely movable shuttle 34, 35. Moreover, at the outer ends of the cylinder are mounted a pair of stops 36, 37 respectively, the setting of which can be varied by means of a fluid pressure operable piston 38. This piston is loaded by means of a coiled compression spring 39 in one direction, and is moved in opposition to the spring by fuel under pressure derived directly from the outlet of the feed pump. The piston has mounted therein a pair of members 40 which have cam surfaces defined on their sides which are presented to the stops. Moreover, the members are adjustably mounted within the piston, and can be adjusted by means of a pair of adjustors 41 respectively operable from the exterior of the apparatus. In the particular example, the cam surfaces are shaped so that as the output pressure of the feed pump increases, the permitted extent of movement of the shuttles within their cylinders is reduced.

At another point on the periphery of the distributor there is formed four equiangularly spaced supply grooves 42 which are in communication with the outlet 15 of the feed pump by way of the passage 29. The supply grooves are angularly aligned with the inlet passages 26, and are arranged to register in turn with a pair of supply ports 43 formed in the body part and which are in communication with the outer ends of the cylinders 32, 33 respectively. Furthermore, at another point the periphery of the distributor member is provided with four equiangularly spaced drain grooves 44 which are in communication by way of a passage (not shown) with a drain defined by free space within the body part of the apparatus, and the drain grooves 44 are angularly aligned with the feed grooves 27. The drain grooves register in turn with a pair of circumferentially spaced drain ports 45 which communicate with the outer ends of the cylinders 32, 33 respectively, and the drain ports 45 are angularly aligned with the supply ports 43 respec tively.

In operation, when one of the inlet passages 26 moves into register wtih an inlet port, e.g., port 30, the shuttle 34 associated therewith is moved inwardly by the action of fuel flowing to the outer end of the end of the cylinder 32 by way of the associated supply port 43 and one of the supply grooves 42. Thus the fuel which was previously contained within the inner end of the cylinder is displaced to the injection pump. At the same time the inlet port 31 is in register with one of the feed grooves 27, and fuel flows to the inner end of the cylinder 33 under the control of the throttle 28, and the shuttle 35 is moved outwardly. Fuel flows from the outer end of this cylinder through the associated drain port 45 and one of the drain grooves 44. Thus a predetermined quantity of fuel is stored at the inner end of the cylinder 33. As the distributor further rotates, the delivery passage 23 is brought into register with one of the outlet ports 24 and meanwhile the feed groove and the inlet passage are moved out of register with both inlet ports. During this time inward movement is imparted to the plungers and fuelis delivered by the injection pump to the outlet port. During further rotation of the distributor member, the delivery passage 23 is moved out of register with the outlet port 24, and a feed groove 27 moves into register with an inlet port and an inlet passage is moved into register with the other inlet port, and the filling of one of the cylinders and the filling of the injection pump takes place as described above. Thus between each injection stroke of the injection pump, one of the shuttles moves inwardly to supply a fresh quantity of fuel to the injection pump, whilst the other shuttle moves ,outwardly ready for inward movement during the next filling stroke.

In this manner it is possible to provide without any difliculty, a distributor type fuel pumping apparatus which is capable of supplying fuel to an eight cylinder engine, and which is provided with a throttle and an inlet metering shuttle. The pumping apparatus having all the advantages of this particular form of apparatus.

Having thus described our invention what we claim as new and desire to secure by Letters Patent is:

1. A liquid fuel pumping apparatus for supplying fuel to an internal combustion engine having an even number of cylinders, the apparatus being of the kind comprising an injection pump which is adapted to be driven in timed relationship with the engine and which during an injection stroke, delivers a predetermined quantity of fuel, a rotary distributor member, mounted within a body, a plurality of outlet ports in the body, a delivery passage formed in said member and communicating with said injection pump, said distributor member also being driven in timed relationship with the engine so that the delivery passage registers in turn during an injection stroke with an outlet port, an inlet passage formed in the distributor member, said inlet passage also communicating with the injection pump, a feed pump for supplying fuel under pressure, a throttle for controlling the quantity of fuel supplied to the injection pump from the feed pump, a pair of inlet ports in the body and with which the inlet passage is arranged to register alternately during successive filling strokes, a pair of cylinders formed in the body, said inlet ports being in communication respectively with one end of said pair of cylinders, a slidable shuttle contained in each cylinder, a feed groove on the distributor member in communication with the feed pump by way of the throttle and through which fuel from the feed pump under the control of the throttle, flows to said ends of the cylinders for subsequent delivery to the injection pump.

2. An apparatus as claimed in claim 1 including first means whereby the other end of the cylinder whose one end is in communication with the inlet passage, is placed in communication with the outlet of the feed pump thereby to move the shuttle therein towards said one end of the cylinder and to displace the fuel contained in said one end of the cylinder to the injection pump and second means whereby the other end of the other cylinder whose one end is in communication with the feed groove is placed in communication with a drain thereby to permit the shuttle therein to move towards said other end of the cylinder.

3. An apparatus as claimed in claim 2 including stop means for limiting the extent of movement of the shuttles towards the other end of their cylinders.

4. An apparatus as claimed in claim 3 in which the setting of said stop means and therefore the permitted extent of movement of the shuttles towards said other end of the cylinders is varied in accordance with the speed at which the apparatus is operated.

5. An apparatus as claimed in claim 4 in which said first and second means comprise grooves formed on the periphery of the distributor member and in communication with the outlet of the feed pump and a drain respectively.

6. An apparatus as claimed in claim 5 in which said stop means comprises a fluid pressure operable spring loaded piston, a pair of cylindrical stops coaxially positioned relative to the cylinders respectively andagainst which the shuttles respectively can bear, a pair of members adjustably mounted in the piston, the surfaces of said members which are presented to the stops defining cam surfaces, and a pair of adjusters whereby the positions of the members relative to the piston can be adjusted, the arrangement being such that axial movement of the piston will effect variation in the setting of the stops.

References Cited UNITED STATES PATENTS 3,107,661 10/1963 Kemp 123139 3,194,225 7/1965 Kemp. 3,263,614 8/ 1966 Kemp. 3,292,546 12/.1966- Evans 1032 3,319,616 5/1967 Glikin 123139 3,433,160 3/1969 Kemp.

DONLEY J. STOCKING, Primary Examiner W. J. KRAUSS, Assistant Examiner US. Cl. X.R. 

